Malicious PDF — malware analysis report

Static analysis result for SHA-256 5d81523562241865…

MALICIOUS

PDF

85.0 KB Created: 2021-09-06 08:20:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 87056a61cc53bbd22c9f4140603801c9 SHA-1: 3d544c22b1b08f61d39a885f5fee34255902b51b SHA-256: 5d81523562241865b384c0c5ae43671ea0e5acbbe184eb98846975583d620dfd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many hosted on compromised WordPress sites or disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and link farm heuristic point towards a phishing or malware distribution attack pattern, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://medvor.ru/uplcv?utm_term=sony+rx100+iii+manual
    • https://spiuruguay.com/ckfinder/userfiles/files/zevarizoweparaw.pdf
    • http://chinajessie.com/seadata/data/uploads/img/file/162925120443.pdf
    • https://xn--z4qq44i.tw/upload/actfiles/69430359437.pdf
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160966c676dd3a---24846511571.pdf
    • http://sugarfree-gelato.com/upload/file/14445194175.pdf
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf98907dd7c---xutikudajutomejolosod.pdf
    • http://transgusto.ch/userfiles/file/laropanenakivufat.pdf
    • https://prawobrzeze.info/userfiles/file/zuzalejikafezazafegum.pdf
    • http://ventilatoryzlin.cz/images/file/74194870314.pdf
    • http://dobrejaja.com/Upload/file/ruzevuwexalusujobosel.pdf
    • https://pernambucoimortal.com/imagens/files/66146502299.pdf
    • http://demenagements-remond.fr/userfiles/file/20210815022118.pdf
    • https://sasalidayanisma.org/uploads/file/22374413700.pdf
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/e45fd2f2a1e56e6a9f2d6e082fb862ed/zanifakev.pdf
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1608eed235b0a3---piguxijiwadinugu.pdf
    • https://kingdomofgodmn.org/userfiles/files/fesarojekobumibukolag.pdf
    • http://krukaiart.com/userfiles/files/91471331415.pdf
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/c1644516c8f0e2f025b0f0f9485bbfe2/2660035019.pdf
    • https://monacollection.ua/wp-content/plugins/super-forms/uploads/php/files/659bad77a1085ce722805f10734c59a9/tedigobalepefedalez.pdf
    • https://torgradio.ru/new/files/file/budiwemo.pdf
    • http://jatyn.cn/upfiles/202105/file/1621245450.pdf
    • https://mediaskills.rs/files/82598617737.pdf
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/d3de619239ed6560b23dcaef79efca22/98895384311.pdf
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070e99a34c2a---vogezejenizasabevudopa.pdf
    • https://agermag.ro/mm/file/12083331193.pdf
    • http://iraneto.com/basefile/iranetocom/files/39724651967.pdf
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612a11033e009---kibegegut.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e807.bin
2974eecaa1ede985dbf5e2d363002a6cdefbd716e349510908b9c76fc645b4b3
pdf-font-stream PDF embedded font (sfnt) at offset 0xE807 10436 bytes
font_01_sfnt_off0000ffb0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFB0 16792 bytes
font_02_sfnt_off000117c2.bin
b0e953fd47b2b1db15fb3d207cc2c3ee607798e9cb24257c7e7aa1860873b29c
pdf-font-stream PDF embedded font (sfnt) at offset 0x117C2 17804 bytes